Stent

ABSTRACT

A stent comprises a plurality of circumferential bands. Circumferential bands which are adjacent one another are connected one to the other. The circumferential bands include peaks and troughs interconnected by bent struts. The bands may overlap or may be connected by connectors.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application is a divisional application of U.S. application Ser.No. 10/063,179, filed on Mar. 28, 2002, which is a continuation-in-partapplication of U.S. application Ser. No. 10/042,634, filed Jan. 9, 2002,which is a continuation-in-part application, claiming priority from U.S.application Ser. No. 09/957,983 filed Sep. 21, 2001 which claims thebenefit of U.S. provisional applications No. 60/234,548, filed Sep. 22,2000, No. 60/272,651 filed Mar. 1, 2001 and No. 60/272,906 filed Mar. 1,2001, all of which are incorporated herein in their entirety byreference.

BACKGROUND OF INVENTION

The use of stents in bodily lumen is well known. A stent is typicallydelivered in an unexpanded state to a desired location in a bodily lumenand then expanded. The stent may be expanded via the use of mechanicaldevice such as a balloon or the stent may be self-expanding.

Because a stent often must be delivered through tortuous anatomy, it isdesirable for the stent to be flexible. Increased flexibility in astent, however, typically comes at the expense of scaffolding strength.Moreover, design features which may result in increased flexibility mayalso result in protruding edges which may damage vessels walls orcatheter balloons during delivery of the stent through tortuousvasculature.

Many stents of conventional design include a plurality of serpentinebands which define openings in the sidewall of the stent. Typically, theopenings are parallel to the longitudinal axis of the stent. Stents havebeen produced with openings which are oblique relative to thelongitudinal axis of the stent. Stents where all of the openings areparallel to one another, however, may experience excessive torque upondelivery through tortuous vessels and resultant deployment problems.

There remains a need for a stent which has a high degree of flexibilityin the unexpanded state, has adequate scaffolding strength and whichdoes not experience excessive torque on delivery.

All US patents and all other published documents mentioned anywhere inthis application are incorporated herein by reference in their entirety.

Without limiting the scope of the invention, a brief summary of theclaimed embodiments of the invention is set forth below. Additionaldetails of the summarized embodiments of the invention and/or additionalembodiments of the invention may be found in the Detailed Description ofthe Invention below.

A brief abstract of the technical disclosure in the specification isprovided as well for the purposes of complying with 37 C.F.R. 1.72.

SUMMARY OF INVENTION

In one embodiment, the invention is directed to a stent comprising aplurality of circumferential bands, circumferential bands which areadjacent one another connected one to the other, the stent includingfirst circumferential bands characterized by a first number ofalternating first peaks and first troughs joined by bent struts andsecond circumferential bands characterized by a second number ofalternating second peaks and second troughs joined by bent struts, thesecond number different from the first number.

The first and second circumferential bands each define a pathway aroundthe periphery of the stent. The first and second pathways may be of thesame length or of different lengths.

Desirably, the first and second peaks and first and second troughs areoriented at an angle between 0° and 70° with respect to the longitudinalaxis of the stent. More desirably, the first and second peaks and firstand second troughs are oriented at an angle of at least 10 degrees withrespect to the longitudinal axis of the stent and most desirably, thefirst and second peaks and first and second troughs are oriented at anangle of at least 15 degrees with respect to the longitudinal axis ofthe stent.

Typically, the first and second circumferential bands may becharacterized by a longitudinal extent with the longitudinal extent ofeach first circumferential band desirably exceeding the longitudinalextent of each second circumferential band.

Optionally, each of the bent struts may be characterized by a width withthe width of the bent struts of the first bands exceeding the width ofthe bent struts of the second bands.

Desirably, bent struts which are circumferentially adjacent one anotherare parallel to one another. More desirably, bent struts inlongitudinally adjacent first and second circumferential bands arenon-parallel to one another.

In one embodiment of the invention, first and second circumferentialbands which are longitudinally adjacent to one another are connected byat least one connector and desirably, by a plurality of connectors.Typically, the connectors will be straight and non-parallel to thelongitudinal axis of the stent. Desirably, the connectors extend frompeaks of circumferential bands to troughs of adjacent circumferentialbands. Also desirably, the connectors are shorter in length than thelongitudinal extent of the second circumferential bands.

Where a plurality of connectors are present between adjacent first andsecond circumferential bands, circumferentially adjacent connectors arejoined via a first pathway along a first circumferential band and asecond pathway along a second circumferential band. The first pathway isdesirably of the same length as the second pathway.

In one embodiment, each first pathway traverses a total of three peaksand troughs (i.e. two peaks and one trough or one peak and two troughs)and each second pathway traverse a total of five peaks and troughs (i.e.three peaks and two troughs or two peaks and three troughs).

In yet another embodiment, the invention is directed to a stentcomprising a plurality of circumferential bands where circumferentialbands which are adjacent one another are connected one to the other. Thecircumferential bands include first circumferential bands characterizedby a first number of alternating first peaks and first troughs andsecond circumferential bands characterized by a second number ofalternating second peaks and second troughs. The second number isdifferent from the first number. The first peaks and troughs areoriented non-parallel to the longitudinal axis of the stent and thesecond peaks and second troughs are oriented non-parallel to thelongitudinal axis of the stent. Optionally, the first and secondcircumferential bands each define a pathway around the periphery of thestent and the first and second pathways are the same length.

Desirably, the peaks and troughs are oriented at an angle of at least 10degrees with respect to the longitudinal axis of the stent. Moredesirably, the peaks and troughs are oriented at an angle of at least 15degrees with respect to the longitudinal axis of the stent.

Desirably, the first and second circumferential bands are eachcharacterized by a longitudinal extent with the longitudinal extent ofthe first circumferential bands exceeding the longitudinal extent of thesecond circumferential bands.

Also desirably, first peaks and first troughs which arecircumferentially adjacent one another are connected by struts andsecond peaks and second troughs which are circumferentially adjacent oneanother are connected by struts. Each of the struts is characterized bya width. The width of the struts of the first bands exceeds the width ofthe struts of the second bands. Typically, struts which arecircumferentially adjacent one another are parallel to one another.

First and second circumferential bands which are longitudinally adjacentone another may be connected by a single connector or by a plurality ofconnectors. The connectors may be of any shape. In one embodiment,straight connectors are used. The connectors may be oriented parallel tothe longitudinal axis or, in another embodiment, non-parallel to thelongitudinal axis. Connectors with curved portions may also be used.

The connectors may extend from any region of one band to any region ofan adjacent band. In one embodiment, the connectors extend from peaks ofcircumferential bands to troughs of adjacent circumferential bands. Inone desirable embodiment, first and second circumferential bands whichare longitudinally adjacent one another are connected by a plurality ofconnectors and the connectors are shorter in length than thelongitudinal extent of the second circumferential bands.Circumferentially adjacent connectors may be joined via a first pathwayalong a first circumferential band and a second pathway along a secondcircumferential band with the first pathway being of the same length asthe second pathway.

Desirably, the struts in first bands which are longitudinally adjacentone another are non-parallel to one another. More desirably, the strutsin first bands which are longitudinally adjacent one another slant inopposing directions relative to the longitudinal axis of the stent.

In yet another embodiment of the invention, the first circumferentialbands are connected to the second circumferential bands via straightconnectors which extend between portions of similar curvature onadjacent circumferential bands. Desirably, the connectors extend betweenpeaks of first circumferential bands and peaks of second circumferentialbands and between troughs of second circumferential bands and troughs offirst circumferential bands.

Typically, the connectors are shorter in length than the longitudinalextent L of first circumferential bands.

In another embodiment, the invention is directed to a stent comprising asidewall with a plurality of openings therein. Each opening is boundedby at least a first stent member and a second stent member. The firststent member is of a larger width than the second stent member. Thefirst stent member comprises a plurality of bent first struts whichextend non-parallel to the longitudinal axis of the stent and the secondstent member comprises a plurality of bent second struts which extendnon-parallel to the longitudinal axis of the stent. The bent firststruts define finger like first projections which are non-parallel tothe longitudinal axis of the stent and the bent second struts definefinger like second projections which are non-parallel to thelongitudinal axis of the stent with the number of second projectionsexceeding the number of first projections.

In one embodiment, each opening is defined by first projections whichare nonparallel to the second projections.

In another embodiment, the openings comprise first openings and secondopenings, with each first opening defined by first projections which areparallel to the second projections. Typically each second opening isdefined by first projections which are non-parallel to secondprojections.

In another embodiment, the invention is directed to a stent comprising asidewall, the sidewall having a plurality of openings therein. Eachopening is bounded by at least a first stent member and a second stentmember. The first stent member is of a larger width than the secondstent member. The first stent member comprises a plurality of bent firststruts which extend non-parallel to the longitudinal axis of the stentand the second stent member comprises a plurality of bent second strutswhich extend non-parallel to the longitudinal axis of the stent. Thebent first struts define finger like first projections which arenon-parallel to the longitudinal axis of the stent and the bent secondstruts define finger like second projections which are nonparallel tothe longitudinal axis of the stent. The number of first projectionsexceeds the number of second projections.

In yet another embodiment, the invention is directed to a stentcomprising a plurality of adjacent connected circumferential bands,including first circumferential bands characterized by a first number ofalternating first peaks and first troughs joined by bent struts andsecond circumferential bands characterized by a second number ofalternating second peaks and second troughs joined by bent struts wherethe second number is different from the first number. Each secondcircumferential band is connected to one adjacent first circumferentialband via at least one connector which extends from a peak on theadjacent first circumferential band to a peak on the secondcircumferential band. Each second circumferential band is also connectedto another adjacent first circumferential band via at least oneconnector which extends from a trough on the another firstcircumferential band to a trough on the second circumferential band.

The invention is also directed to a stent comprising a plurality ofconnected serpentine circumferential bands including a first serpentinecircumferential band having a first total circumferential length at aproximal end of the stent, a second serpentine circumferential bandhaving a second total circumferential length at a distal end of thestent and a third serpentine circumferential band having a third totalcircumferential length between the proximal and distal ends of thestent. The first and second total circumferential lengths differ fromone another. Desirably, the first, second and third totalcircumferential lengths differ from one another. More desirably, thefirst and second total circumferential lengths are less than the thirdtotal circumferential length.

The invention is also directed to a stent comprising a plurality ofconnected serpentine circumferential bands. Each serpentinecircumferential band comprises a plurality of peaks and troughs.Adjacent peaks and troughs are connected by bent struts. The serpentinecircumferential bands include a first serpentine circumferential bandhaving a first total circumferential length at a proximal end of thestent, a second serpentine circumferential band having a second totalcircumferential length at a distal end of the stent and a thirdserpentine circumferential band having a third total circumferentiallength between the proximal and distal ends of the stent. At least oneof the first and second total circumferential lengths differs from thethird total circumferential length. Desirably, the first, second andthird total circumferential lengths differ from one another. Moredesirably, the first and second total circumferential lengths are lessthan the third total circumferential length.

The invention is also directed to a stent comprising a plurality ofconnected serpentine circumferential bands. Each serpentinecircumferential band comprises a plurality of peaks and troughs withadjacent peaks and troughs connected by bent struts. Adjacent serpentinecircumferential bands are connected one to the other in one or moreregions of overlap where a peak in one serpentine band overlaps with atrough in an adjacent serpentine circumferential band. The one or moreregions of overlap extend in a longitudinal direction.

The invention is also directed to a stent comprising a plurality ofconnected serpentine circumferential bands. Each serpentinecircumferential band comprises a plurality of peaks and troughs.Adjacent peaks and troughs are connected by nested bent struts.Serpentine circumferential bands which are adjacent one another areconnected via a plurality of connections. The stent includes twoserpentine circumferential bands which are connected via a first numberof connections and two serpentine circumferential bands which areconnected via a second number of connections, the second numberdifferent from the first number.

The invention is also directed to a stent comprising a plurality ofadjacent serpentine circumferential bands containing alternating troughsand peaks. Adjacent serpentine circumferential bands have a plurality ofcells therebetween. At least two adjacent serpentine circumferentialbands have a plurality of first cells therebetween and a plurality ofsecond cells therebetween. The second cells are larger than the firstcells.

The invention is also directed to a stent comprising a plurality ofserpentine circumferential bands including a first serpentinecircumferential band comprising a plurality of peaks and troughs,adjacent peaks and troughs connected by bent struts and a secondserpentine circumferential band comprising a plurality of peaks andtroughs, adjacent peaks and troughs connected by relatively straightstruts. The first and second serpentine circumferential bands areconnected to one another.

Without being bound by theory, bent struts have been found to providemore wall coverage than straight struts. Furthermore, using bent strutstypically requires more material, i.e. metal, and thus provides improvedradiopacity as well.

Additional details and/or embodiments of the invention are discussedbelow.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1a is a flat layout view of an inventive stent.

FIG. 1b shows an enlarged view of region A of the stent shown in flatlayout view in FIG. 1 a.

FIG. 2a is a flat layout view of an embodiment of the inventive stent ofthe present invention which is similar to that shown in FIG. 1 a.

FIG. 2b shows an enlarged view of region A of the stent shown in flatlayout view in FIG. 2 a.

FIG. 3a shows an alternative embodiment of the inventive stent of thepresent invention.

FIG. 3b shows an enlarged view of region A of the stent shown in flatlayout view in FIG. 3 a.

FIG. 4a is a flat layout view of an embodiment of the inventive stent ofthe present invention.

FIG. 4b shows an enlarged view of region A of the stent shown in flatlayout view in FIG. 4 a.

FIG. 5a is a flat layout view of an embodiment of the inventive stent ofthe present invention.

FIG. 5b shows an enlarged view of region A of the stent shown in flatlayout view in FIG. 5 a.

FIG. 6a is a flat layout view of an embodiment of the inventive stent ofthe present invention.

FIG. 6b shows an enlarged view of region A of the stent shown in flatlayout view in FIG. 6 a.

FIG. 7a is a flat layout view of an embodiment of the inventive stent ofthe present invention.

FIG. 7b shows an enlarged view of region A of the stent shown in flatlayout view in FIG. 7 a.

FIG. 8a is a flat layout view of an embodiment of the inventive stent ofthe present invention.

FIG. 8b shows an enlarged view of region A of the stent shown in flatlayout view in FIG. 8 a.

FIG. 9a is a flat layout view of an inventive stent of the presentinvention.

FIG. 9b shows an enlarged view of region A of the stent shown in flatlayout view in FIG. 9 a.

FIG. 10a is a flat layout view of an inventive stent of the presentinvention.

FIG. 10b shows an enlarged view of region A of the stent shown in flatlayout view in FIG. 9 a.

FIG. 11 shows a flat layout view of an alternative embodiment of theinventive stent of the present invention.

FIG. 12-19 show flat layout views of other embodiments of the inventivestents of the present invention, the stents having large and smallamplitude circumferential bands.

FIGS. 20-25 show flat layout views of other embodiments of the inventivestents of the present invention, the stents having circumferential bandsof the same amplitude.

FIGS. 26-45 show flat layout views of other embodiments of the inventivestents of the present invention, the stents having overlappingcircumferential bands.

FIG. 46 shows other connectors which may be used in the inventivestents.

DETAILED DESCRIPTION

While this invention may be embodied in many different forms, there aredescribed in detail herein specific embodiments of the invention. Thisdescription is an exemplification of the principles of the invention andis not intended to limit the invention to the particular embodimentsillustrated.

For the purposes of this disclosure, like reference numerals in thefigures shall refer to like features unless otherwise indicated.

Also for the purposes of this disclosure, the term ‘bent strut’ does notimplicate a method of manufacture and is intended to include strutswhich have curves, struts which are angled, and struts which arecurvilinear, regardless of how the struts or the stent as a whole aremanufactured. Bent struts as referred to herein typically have twosegments joined by a bent portion.

Finally, for the purposes of this disclosure, the expression ‘totalcircumferential length’ refers to the length of a circumferential bandas the band is traversed about the circumference of the stent.

In one embodiment, the invention is directed to a stent such as thatshown by way of example at 100 in FIG. 1a comprising a plurality ofcircumferential bands. Circumferential bands which are adjacent oneanother are connected one to the other. The circumferential bandsinclude first circumferential bands 104 characterized by a first numberof alternating first peaks 106 and first troughs 108 joined by bentstruts 110 and second circumferential bands 112 characterized by asecond number of alternating second peaks 114 and second troughs 116joined by bent struts, 118. Typically, as shown in FIG. 1a , the secondnumber of second peaks and troughs is different from the first number offirst peaks and troughs and desirably exceeds the first number.

The first and second circumferential bands each define a pathway aroundthe periphery of the stent. The first and second pathways may be of thesame length or of different lengths. Desirably, the first and secondpathways are the same length.

Also desirably, the first and second peaks and first and second troughsare oriented at an angle between 0° and 70° with respect to thelongitudinal axis of the stent, more desirably they are oriented at anangle of at least 10 degrees with respect to the longitudinal axis ofthe stent, and most desirably, the first and second peaks and first andsecond troughs are oriented at an angle of at least 15 degrees withrespect to the longitudinal axis of the stent.

Typically, as shown in FIG. 1b , the first and second circumferentialbands may be characterized by longitudinal extents L₁ and L₂. Thelongitudinal extent of each first circumferential band L₁ desirablyexceeds the longitudinal extent L₂ of the individual secondcircumferential bands.

Each of the bent struts may be characterized by a width. Optionally, thewidth of the bent struts of the first bands W₁ exceeds the width of thebent struts of the second bands W₂.

Desirably, as shown in FIG. 1a , bent struts which are circumferentiallyadjacent one another are parallel to one another. More desirably, asshown in FIG. 1a , bent struts in longitudinally adjacent first andsecond circumferential bands are non-parallel to one another.

In one embodiment of the invention, as shown in FIG. 1a , first andsecond circumferential bands which are longitudinally adjacent oneanother are connected by at least one connector 120 and desirably, by aplurality of connectors. Typically, the connectors will be straight andnon-parallel to the longitudinal axis 101 of the stent. In otherembodiments of the invention, other types of connectors may be used forexample connectors with one or more curves and/or connectors ofdifferent lengths. Desirably, as shown in FIG. 1 a, the connectorsextend from peaks of circumferential bands to troughs of adjacentcircumferential bands. Also desirably, as shown in FIG. 1a , theconnectors are shorter in length than the longitudinal extent L.sub.2 ofthe second circumferential bands.

Where a plurality of connectors are present between adjacent first andsecond circumferential bands, circumferentially adjacent connectors arejoined via a first pathway along a first circumferential band and asecond pathway along a second circumferential band, the first pathwaydesirably being of the same length as the second pathway.

In the embodiment of FIG. 1a , each first pathway traverses a total ofthree peaks and troughs (i.e. two peaks and one trough or one peak andtwo troughs) and each second pathway traverse a total of five peaks andtroughs (i.e. three peaks and two troughs or two peaks and threetroughs).

In other words, between circumferentially adjacent connectors whichconnect first and second circumferential bands together, in the firstband, there are a total of three peaks and troughs between theconnectors, and in the second circumferential band there are a total offive peaks and troughs between connectors.

Without being bound by theory, the alternating orientation of adjacentfirst and second circumferential bands is believed to preventsignificant rotation and build-up of torque and the accompanyingdegradation of stent performance.

In another embodiment, the invention is directed to a stent such as thatshown by way of example at 100 in FIG. 2a comprising a plurality ofcircumferential bands substantially similar to those shown in FIG. 1a .As in the embodiment shown in FIG. 1a , the first and secondcircumferential bands each define a pathway around the periphery of thestent. The first and second pathways may be of the same length or ofdifferent lengths. Desirably, the first and second pathways are the samelength.

Also as in the embodiment shown in FIG. 1a , the first circumferentialbands 104 are characterized by a first number of alternating first peaks106 and first troughs 108 joined by bent struts 110 and secondcircumferential bands 112 characterized by a second number ofalternating second peaks 114 and second troughs 116 joined by bentstruts, 118. Typically, as shown in FIG. 1a , the second number ofsecond peaks and troughs is different from the first number of firstpeaks and troughs and desirably exceeds the first number.

In the embodiment shown in FIG. 2a , however, in contrast to that shownin FIG. 1a , the connectors do not extend between the nearestneighboring peaks and troughs, but rather every first peak of everyfirst circumferential band 104 is connected to every third trough of asecond adjacent circumferential band.

As in FIG. 1b , the first and second circumferential bands may becharacterized by longitudinal extents L₁ and L₂ as shown in FIG. 2b .The longitudinal extent of each first circumferential band L₁ desirablyexceeds the longitudinal extent L₂ of the individual secondcircumferential bands.

Again as in FIG. 1a , the first and second circumferential bands whichare longitudinally adjacent one another are connected by at least oneconnector 120 and desirably, by a plurality of connectors. Desirably, asshown in FIG. 2a , the connectors extend from peaks of circumferentialbands to troughs of adjacent circumferential bands as in FIG. 1a .However, in the embodiment shown in FIG. 2a , the connectors aresignificantly longer in length than the longitudinal extent L₂ of thesecond circumferential bands.

Where a plurality of connectors are present between adjacent first andsecond circumferential bands, circumferentially adjacent connectors arejoined via a first pathway along a first circumferential band and asecond pathway along a second circumferential band, the first pathwaydesirably being of the same length as the second pathway.

In the embodiment shown in FIG. 2a , each first pathway traverses atotal of four peaks and troughs (i.e. two peaks and two troughs) andeach second pathway traverse a total of six peaks and troughs (i.e.three peaks and three troughs).

In another embodiment, the invention is directed to a stent such as thatshown by way of example at 300 in FIG. 3a comprising a plurality ofcircumferential bands. This embodiment is also similar to theembodiments shown in FIGS. 1a and 2 a.

Circumferential bands which are adjacent one another are connected oneto the other. The circumferential bands include first circumferentialbands 304 characterized by a first number of alternating first peaks 306and first troughs 308 joined by bent struts 310 and secondcircumferential bands 312 characterized by a second number ofalternating second peaks 314 and second troughs 316 joined by bentstruts. The number of second peaks and troughs is different from thenumber of first peaks and troughs and desirably exceeds the firstnumber.

The first and second circumferential bands each define a pathway aroundthe periphery of the stent. The first and second pathways may be of thesame length or of different lengths but are desirably the same length.

As shown in FIG. 3b , the first and second troughs are oriented at anangle of at least 10 degrees with respect to the longitudinal axis 301of the stent. More desirably, the first and second peaks and first andsecond troughs are oriented at an angle of at least 15 degrees withrespect to the longitudinal axis of the stent. In the particularembodiment shown in FIG. 3b , the first and second peaks and first andsecond troughs, are actually oriented at an angle of about 40 degreeswith respect to the longitudinal axis of the stent.

Typically, as shown in FIG. 3b , the first and second circumferentialbands may be characterized by longitudinal lengths L₁ and L₂ which maybe of the same length, or of a different length. Desirably, L₁ exceedsthe longitudinal extent L₂ of the individual second circumferentialbands.

Each of the bent struts may be characterized by a width. Optionally, thewidth of the bent struts of the first bands W₁ exceeds the width of thebent struts of the second bands W₂.

The first and second circumferential bands which are longitudinallyadjacent one another are connected by at least one connector 320 andpreferably by a plurality of connectors. In this particular embodiment,the connectors are straight, and are nonparallel to the longitudinalaxis 301 of the stent 300. Also in the embodiment shown in FIG. 3a , theconnectors are significantly shorter than the longitudinal extent of thecircumferential bands L₂. Other connectors may be optionally used,however including connectors having more curves or being of a differentlength.

In this embodiment, the connectors extend between peaks ofcircumferential bands to troughs of adjacent circumferential bands. Inthis particular embodiment, the connectors are shorter in length thanthe extent L₂ of the second circumferential bands.

This may be optionally described in terms of first and second pathways.Where a plurality of connectors are present between adjacent first andsecond circumferential bands, circumferentially adjacent connectors arejoined via a first pathway along a first circumferential band and asecond pathway along a second circumferential band, the first pathwaydesirably being of the same length as the second pathway.

In the embodiment shown in FIG. 3a , the first pathway traverses a totalof four peaks and troughs (two peaks and two troughs) and the secondpathway traverses a total of six peaks and troughs (three peaks andthree troughs).

FIG. 4a illustrates an embodiment similar to those shown in FIGS. 1a-3aas described above.

Again, there are first and second circumferential bands which define apathway around the periphery of the stent. The first and second pathwaysmay be of the same length or of different lengths but are desirably thesame length.

The first and second circumferential bands which are longitudinallyadjacent one another are connected by at least one connector 420 andpreferably by a plurality of connectors. In this particular embodiment,the connectors are straight, and are nonparallel to the longitudinalaxis 401 of the stent 400. Other connectors may be optionally used,however including connectors having more curves or being of a differentlength.

In this embodiment, the connectors extend between peaks ofcircumferential bands to troughs of adjacent circumferential bands. Inthis particular embodiment, the connectors are shorter in length thanthe extent L₂ of the second circumferential bands.

This may be optionally described in terms of first and second pathways.Where a plurality of connectors are present between adjacent first andsecond circumferential bands, circumferentially adjacent connectors arejoined via a first pathway along a first circumferential band and asecond pathway along a second circumferential band, the first pathwaydesirably being of the same length as the second pathway.

Again, as in the embodiment shown in FIG. 3a , the embodiment shown inFIG. 4a includes a first pathway which traverses a total of four peaksand troughs (two peaks and two troughs) and the second pathway traversesa total of six peaks and troughs (three peaks and three troughs).

The connectors in the embodiment shown in FIG. 4a are at a differentangle relative to the longitudinal axis 401 of stent 400 than thoseshown in FIG. 3a , the angle being smaller relative to the longitudinalaxis in the embodiment shown in FIG. 4 a.

An alternative embodiment of the inventive stent of the presentinvention is shown generally at 500 in FIG. 5a and again includes aplurality of circumferential bands. Circumferential bands which areadjacent one another are connected one to the other. The circumferentialbands include first circumferential bands 504 characterized by a firstnumber of alternating first peaks 506 and first troughs 508 joined bybent struts 510 and second circumferential bands 512 characterized by asecond number of alternating second peaks 514 and second troughs 516joined by bent struts 518. In this particular embodiment, the number ofsecond peaks and troughs is the same as the number of first peaks andtroughs.

The first and second circumferential bands each define a pathway aroundthe periphery of the stent. The first and second pathways may be of thesame length or of a different length. In the embodiment shown in FIG. 5a, the first and second pathways are of the same length.

The first and second peaks and first and second troughs are oriented atan angle of at least 10 degrees with respect to the longitudinal axis501 of the stent 500, and desirably are oriented at an angle of at least15 degrees with respect to the longitudinal axis 501.

In this particular embodiment, as shown in FIG. 5b , the longitudinalextent L₁ of the first circumferential band is substantially equal inlength to the longitudinal extent L₂ of the second circumferential band.

Also in the embodiment shown in FIG. 5b , the width of each of the bentstruts of the first bands W₁ is equal to the width of the bent struts ofthe second bands W2 Optionally, the widths may be different. Forexample, the width of the first bands W may exceed the width of thesecond bands W₂.

In the embodiment shown in FIG. 5a , first and second circumferentialbands which are longitudinally adjacent one another are connected by atleast one connector 520 and desirably, by a plurality of connectors.Typically, in this embodiment, the connectors will be curved as opposedto the straight connectors as shown in some of the other embodiments. Inthis embodiment, the connectors extend from the troughs ofcircumferential bands to troughs of adjacent circumferential bands. Theconnectors are shown longer in length than the longitudinal extents L₁and L₂ of the circumferential bands.

Where a plurality of connectors are present between adjacent first andsecond circumferential bands, circumferentially adjacent connectors arejoined via a first pathway along a first circumferential band and asecond pathway along a second circumferential band, the first pathwaydesirably being of the same length as the second pathway. Each firstpathway traverses a total of six peaks and troughs (three peaks andthree troughs) and each second pathway traverses a total of six peaksand troughs (three peaks and three troughs).

In yet another alternative embodiment of the inventive stent of thepresent invention shown generally at 600 in FIG. 6a , the stent includesa plurality of circumferential bands wherein circumferential bands whichare adjacent one another are connected one to the other. Thecircumferential bands include first circumferential bands 604characterized by a first number of alternating first peaks 606 and firsttroughs 608 and second circumferential bands 612 characterized by asecond number of alternating second peaks 614 and second troughs 616.The second number is different from the first number. The first peaksand troughs are oriented non-parallel to the longitudinal axis 601 ofthe stent 600 and the second peaks and second troughs are orientednon-parallel to the longitudinal axis 601 of the stent. Desirably, thepeaks and troughs are oriented at an angle of at least 10 degrees withrespect to the longitudinal axis of the stent. More desirably, the peaksand troughs are oriented at an angle of at least 15 degrees with respectto the longitudinal axis of the stent.

The first and second circumferential bands each define a pathway aroundthe periphery of the stent and the first and second pathways are thesame length.

The stent is further characterized by bent struts which exhibit aconfiguration similar to finger-like projections. Each of the bentstruts may be characterized by a width. Optionally, the width of thebent struts of the first bands W₁ exceeds the width of the bent strutsof the second bands W₂.

Desirably, as shown in FIG. 6a , bent struts which are circumferentiallyadjacent one another are parallel to one another. Bent struts inlongitudinally adjacent first and second circumferential bands may ormay not be parallel to one another, however.

In the embodiment shown in FIG. 6a , first and second circumferentialbands which are longitudinally adjacent one another are connected by atleast one connector 620 and desirably, by a plurality of connectors.Typically, the connectors will be substantially straight andnon-parallel to the longitudinal axis 601 of the stent. In otherembodiments of the invention, other types of connectors may be used forexample connectors with one or more curves and/or connectors ofdifferent lengths. Desirably, as shown in FIG. 6a , the connectorsextend from peaks of circumferential bands to troughs of adjacentcircumferential bands. Also desirably, as shown in FIG. 6a , theconnectors are similar in length to the longitudinal extent L of thesecond circumferential bands.

Where a plurality of connectors are present between adjacent first andsecond circumferential bands, circumferentially adjacent connectors arejoined via a first pathway along a first circumferential band and asecond pathway along a second circumferential band, the first pathwaydesirably being of the same length as the second pathway.

In the embodiment of FIG. 6a , each first pathway traverses a total offour peaks and troughs (i.e. two peaks and two troughs) and each secondpathway traverse a total of six peaks and troughs (i.e. three peaks andthree troughs).

Yet another alternative embodiment of the inventive stent of the presentinvention is shown generally at 700 in FIG. 7a , the stent includes aplurality of circumferential bands wherein circumferential bands whichare adjacent one another are connected one to the other. Thecircumferential bands include first circumferential bands 704characterized by a first number of alternating first peaks 706 and firsttroughs 708 and second circumferential bands 712 characterized by asecond number of alternating second peaks 714 and second troughs 716.The second number is different from the first number. The first peaksand troughs are oriented non-parallel to the longitudinal axis 701 ofthe stent 700 and the second peaks and second troughs are orientednon-parallel to the longitudinal axis 701 of the stent. Desirably, thepeaks and troughs are oriented at an angle of at least 10 degrees withrespect to the longitudinal axis of the stent. More desirably, the peaksand troughs are oriented at an angle of at least 15 degrees with respectto the longitudinal axis of the stent.

The first and second circumferential bands each define a pathway aroundthe periphery of the stent and the first and second pathways are thesame length.

The stent is further characterized as having bent struts exhibitingfinger-like projections which are similar to those in the embodimentshown in FIG. 6a . Each of the bent struts may be characterized by awidth. Optionally, the width of the bent struts of the first bands W₁exceeds the width of the bent struts of the second bands W₂.

Desirably, as shown in FIG. 7a , bent struts which are circumferentiallyadjacent one another are parallel to one another. Bent struts inlongitudinally adjacent first and second circumferential bands may ormay not be parallel to one another, however.

In the embodiment shown in FIG. 7a , first and second circumferentialbands which are longitudinally adjacent one another are connected by atleast one connector 720 and desirably, by a plurality of connectors.Typically, the connectors are slightly curvilinear and are non-parallelto the longitudinal axis 701 of the stent. In other embodiments of theinvention, other types of connectors may be used for example connectorswith one or more curves and/or connectors of different lengths.Desirably, as shown in FIG. 7a , the connectors extend from peaks ofcircumferential bands to troughs of adjacent circumferential bands. Alsodesirably, as shown in FIG. 7a , the connectors are shorter in lengththan the longitudinal extent L₂ of the second circumferential bands.

Where a plurality of connectors are present between adjacent first andsecond circumferential bands, circumferentially adjacent connectors arejoined via a first pathway along a first circumferential band and asecond pathway along a second circumferential band, the first pathwaydesirably being of the same length as the second pathway.

In the embodiment of FIG. 7a , each first pathway traverses a total offour peaks and troughs (i.e. two peaks and two troughs) and each secondpathway traverse a total of six peaks and troughs (i.e. three peaks andthree troughs).

An alternative embodiment of the inventive stent of the presentinvention is shown in FIG. 8a . In this embodiment, the stent issubstantially similar to that shown in FIG. 7a . The connectors 820shown in the embodiment in FIG. 8a are straight while those shown inFIG. 7a are slightly curvilinear. The connectors 820 are again shorterin shorter in length than the longitudinal extent L₂ of the secondcircumferential bands.

Again, a plurality of connectors are shown present and between adjacentfirst and second circumferential bands. The circumferentially adjacentconnectors are again joined via a first pathway along a firstcircumferential band and a second pathway along a second circumferentialband, the first pathway desirably being of the same length as the secondpathway. Again in the embodiment of FIG. 8a , each first pathwaytraverses a total of four peaks and troughs (i.e. two peaks and twotroughs) and each second pathway traverse a total of six peaks andtroughs (i.e. three peaks and three troughs).

Desirably, as shown in FIG. 9b , the first and second circumferentialbands 204 and 212 are each characterized by a longitudinal extent withthe longitudinal extent L₁ of each the first circumferential bandsexceeding the longitudinal extent L₂ of the second circumferentialbands.

In yet another embodiment, as shown generally at 200 in FIG. 9a , theinvention is directed to a stent including a plurality ofcircumferential bands where circumferential bands which are adjacent oneanother are connected one to the other. The circumferential bandsinclude first circumferential bands 204 characterized by a first numberof alternating first peaks 206 and first troughs 208 and secondcircumferential bands 212 characterized by a second number ofalternating second peaks 214 and second troughs 216. The second numberis different from the first number. The first peaks and troughs areoriented non-parallel to the longitudinal axis 201 of the stent and thesecond peaks and second troughs are oriented non-parallel to thelongitudinal axis of the stent. Desirably, the peaks and troughs areoriented at an angle of at least 10 degrees with respect to thelongitudinal axis of the stent. More desirably, the peaks and troughsare oriented at an angle of at least 15 degrees with respect to thelongitudinal axis of the stent. Optionally, the first and secondcircumferential bands each define a pathway around the periphery of thestent and the first and second pathways are the same length.

Desirably, as shown in FIG. 9b , the first and second circumferentialbands 204 and 212 are each characterized by a longitudinal extent withthe longitudinal extent L₁ of each the first circumferential bandsexceeding the longitudinal extent L₂ of the second circumferentialbands.

Also desirably, first peaks and first troughs which arecircumferentially adjacent one another are connected by struts 218 a andsecond peaks and second troughs which are circumferentially adjacent oneanother are connected by struts 218 b. Each of the struts ischaracterized by a width with the width W₁ of the struts of the firstcircumferential bands exceeding the width W₂ of the struts of the secondcircumferential bands.

Typically, as shown in FIG. 9a , struts which are circumferentiallyadjacent one another are parallel to one another.

First and second circumferential bands which are longitudinally adjacentone another may be connected by a single connector or by a plurality ofconnectors. The connectors may be of any shape. In one embodiment, asshown in FIG. 9a , straight connectors 220 may be used. The connectorsmay be oriented non-parallel to the longitudinal axis, as shown in FIG.9b or, in another embodiment, oriented parallel to the longitudinalaxis.

The connectors may extend from any region of one circumferential band toany region of an adjacent circumferential band. In the embodiment ofFIG. 9a , the connectors extend from peaks of circumferential bands totroughs of adjacent circumferential bands. In the embodiment of FIG. 9a, first and second circumferential bands 204 and 212 which arelongitudinally adjacent one another are connected by a plurality ofconnectors 220 and the connectors are shorter in length than thelongitudinal extent L₂ of the second circumferential bands.Circumferentially adjacent connectors may be joined via a first pathwayalong a first circumferential band and a second pathway along a secondcircumferential band with the first pathway desirably being of the samelength as the second pathway.

Desirably, as shown in FIG. 9a , the struts 218 a in firstcircumferential bands which are longitudinally adjacent one, for examplefirst circumferential bands 204 a and 204 b, are non-parallel to oneanother. More desirably, as shown in FIG. 9a , the struts in firstcircumferential bands which are longitudinally adjacent one anotherslant in opposing directions relative to the longitudinal axis of thestent. Without being bound by theory, the alternating orientation ofadjacent first circumferential bands is believed to prevent significantrotation and build-up of torque and the accompanying degradation ofstent performance.

In another embodiment of the invention, the first circumferential bandsare connected to the second circumferential bands via straightconnectors which extend between portions of similar curvature onadjacent circumferential bands. As shown by way of example in FIG. 10a ,connectors 220 a extend between peaks 206 of first circumferential band204 a and peaks 214 of second circumferential band 212. Connectors 220 bextend between troughs 216 of second circumferential band 212 andtroughs 208 of first circumferential bands 204 b.

In the embodiment of FIG. 10a , connectors 220 a and 220 b are shorterin length than the longitudinal extent L₁ of first circumferential bands204 but longer than the connectors of the embodiment of FIG. 10a . Inother embodiments of the invention, longer connectors may be used. Anyof the other connectors disclosed herein may also be used to achievedifferent properties.

The invention is also directed to other embodiments in which theorientation of the struts in the first circumferential bands alternatesbetween consecutive first circumferential bands relative to thelongitudinal axis. In the embodiment of FIG. 11, the orientation of thestruts in adjacent first circumferential bands 304 a,b relative to thelongitudinal axis alternates. Moreover, each second circumferential band312 a,b may comprise a plurality of consecutive struts 307′ oriented ina first direction relative to the longitudinal axis of the stent and aplurality of consecutive struts 307″ oriented in a second directionopposite the first direction and relative to the longitudinal axis ofthe stent. Adjacent circumferential bands are connected via connectors329. Desirably, in the embodiment of FIG. 11, the connectors areoriented longitudinally. Any of the other connectors disclosed hereinmay be used to achieve stents with other characteristics.

First circumferential bands 304 a,b may be longer or the same lengthabout the periphery of the stent as second circumferential bands 312a,b. First circumferential bands 304 a,b are desirably wider than secondcircumferential bands 312 a,b. Also desirably, the first circumferentialbands have fewer peaks and troughs than the second circumferentialbands.

It is further within the scope of the invention to vary the number ofconnectors extending between adjacent circumferential bands in any ofthe embodiments disclosed herein. For example, adjacent circumferentialbands in the middle of the stent may be joined by more connectors thanadjacent circumferential bands at the proximal and/or distal ends of thestent so that the proximal and/or distal ends of the stent are moreflexible. The middle portion of the stent may have fewer connectors thanthe proximal and/or distal ends of the stent to achieve greaterflexibility in the middle of the stent than in the proximal and/ordistal ends of the stent. The number of connectors may increase over thelength of the stent to provide a stent with increasing rigidity over itslength.

The invention is also directed to a stent such as that shown by way ofexample in FIG. 1a , comprising a sidewall with a plurality of openings122 therein. Each opening is bounded by at least a first stent memberand a second stent member. The first stent member 134 (shown shaded) isof a larger width than the second stent member 142 (shown shaded). Thefirst stent member 134 comprises a plurality of bent first struts 110which extend non-parallel to the longitudinal axis 101 of the stent andthe second stent member 142 comprises a plurality of bent second struts118 which extend non-parallel to the longitudinal axis of the stent. Thebent first struts define finger like first projections 124 (shownshaded) which are non-parallel to the longitudinal axis of the stent andthe bent second struts define finger like second projections 126 whichare non-parallel to the longitudinal axis of the stent with the numberof first projections exceeding the number of second projections.

Desirably, as shown in the embodiment of FIG. 1a , each opening isdefined by first projections which are non-parallel to secondprojections.

In another embodiment, as shown by way of example in FIG. 9a , the stentcomprises a plurality of openings including first openings 222 a andsecond openings 222 b. Each first opening 222 a includes firstprojections 224 a which are parallel to second projections 226 a. Eachsecond opening 222 b includes first projections 224 b which arenon-parallel to second projections 226 b.

The stent of FIG. 9a also has first openings and second openings whereeach first opening includes first projections which are parallel tosecond projections. Each second opening includes first projections whichare non-parallel to second projections.

In another embodiment, the invention is directed to a stent such as thatshown at 100 in FIG. 12 comprising a plurality of circumferential bands.Circumferential bands which are adjacent one another are connected oneto the other. At least a portion of the stent, and, desirably, as shownin FIG. 12, the entirety of the stent consists of first circumferentialbands 104 characterized by a first number of alternating first peaks 106and first troughs 108 joined by bent struts 110 and secondcircumferential bands 112 characterized by a second number ofalternating second peaks 114 and second troughs 116 joined by bentstruts 118. Typically, as shown in FIG. 12, the second number of secondpeaks and troughs is different from the first number of first peaks andtroughs and desirably exceeds the first number. First circumferentialbands which are adjacent to second circumferential bands are connectedthereto by at least one, and desirably, as shown in FIG. 12, a pluralityof connectors 120. Connectors 120 extend from troughs of firstcircumferential bands to troughs of second circumferential bands andfrom peaks of second circumferential bands to peaks of firstcircumferential bands. Connectors 120 are bent and are generallyparallel to the struts of the first circumferential bands.

In the embodiment of FIG. 12, with the exception of the connectors ofthe end bands, each connector which extends in distal direction isseparated by one struts from a connector extending in a distaldirection.

In the embodiment of FIG. 13, adjacent first circumferential bands 104and second circumferential bands 112 are connected to one another viaone and desirably a plurality of connectors 120 which extend from peaks106 of first circumferential bands to troughs 16 of secondcircumferential bands 112 and from peaks 114 of second circumferentialbands 112 to troughs 108 of first circumferential bands 104. Connectors120 are desirably significantly shorter than the struts of the secondcircumferential band 112. More desirably, the length of connectors 120is on the order of magnitude of the width of the struts 110 of firstcircumferential band 104. As shown in FIG. 13, each connector whichextends in a distal direction is separated from a connector extending ina proximal direction by three struts. Connectors 120 are straight andoriented parallel to the longitudinal axis.

In the embodiment of FIG. 13, as well as in many of the otherembodiments of the invention, connectors 120 do not extend from thecenter of the peaks and troughs but rather extend from corners of thepeaks and troughs. In the embodiment of FIG. 12, connectors extend fromthe center of the peaks and troughs.

The individual sections 110 a and 110 b of bent struts 110 of theinventive stent of FIG. 13 extend at a more gradual angle relative tothe longitudinal axis of the stent than the individual sections of thebent struts of the stent of FIG. 12. Specifically, the sections of thebent struts of the stent of FIG. 12 extend at a 40 degree angle relativeto the longitudinal axis and the sections of the bent struts of thestent of FIG. 13 extend at a 30 degree angle relative to thelongitudinal axis.

Depending on the alignment of adjacent circumferential bands, theconnectors may also be at an angle relative to the longitudinal axis asshown in FIG. 14. Connectors 120 are non-parallel to the longitudinalaxis, extending at an oblique angle relative to the longitudinal axis.In the stent of FIG. 14, the orientation of connectors relative to thelongitudinal axis reverses along the length of the stent with connectors120 a extending in a first direction and connectors 120 b extending in asecond opposite direction relative to the longitudinal axis of thestent.

In the embodiment of FIG. 15, the sections 110 a and 110 b of the bentstruts 110 extend at a 40 degree angle relative to the longitudinal axisof the stent. Straight connectors 120 are provided between adjacentcircumferential bands 104 and 112.

In the embodiment of FIG. 16, adjacent first and second circumferentialbands 104 and 112 are spaced further apart from one another than in someof the previous embodiments. As a result, connectors 120 are longer thanin other embodiment where the connectors extend between peaks andtroughs. Also, the bent struts 110 of the first circumferential bands104 are much closer in width to the bent struts 110 of the secondcircumferential bands 112.

FIG. 17 is an embodiment with narrower bent struts in the firstcircumferential bands and with connectors 120 which are parallel to thelongitudinal axis of the stent.

The embodiment of FIG. 18 is similar to that of FIG. 17, differing inpart in that the sections of the bent struts extend at a 40 degree anglerelative to the longitudinal axis rather than the 30 degree angle of thestruts of FIG. 17.

The stent of FIG. 19 comprises first circumferential bands 104 whichhave bent struts 110 and second circumferential bands 112 which haverelatively straight struts which are not parallel to the longitudinalaxis of the stent. The orientation of the struts of the secondcircumferential bands reverses along the length of the stent. Connectors120 extend from peaks 106 of first circumferential bands 104 to peaks114 of second circumferential bands 112 and from troughs 116 of secondcircumferential bands 112 to troughs 108 of first circumferential bands104.

In the embodiment of FIG. 20, adjacent circumferential bands 104 are ofthe same longitudinal extent and have an identical number of peaks 106and an identical number of troughs 108. Connectors 120 extend from peaks106 of circumferential bands 104 to troughs 108 of adjacentcircumferential bands 104 and from troughs 106 of circumferential bands104 to peaks 106 of adjacent circumferential bands 104. The connectors120 are parallel to the longitudinal axis of the stent.

In the embodiment of FIG. 26, adjacent circumferential bands 104 shareone or more members 130 in common. One or more peaks 106 a of onecircumferential band 104 are longer than the remaining peaks 106 b andone or more troughs 108 a of the adjacent circumferential band 104 arelonger than the remaining troughs 108 b. The longer peaks 106 aintersect with the longer troughs 108 a and share a member 130 in commonforming an H-shaped structure 132. The resulting H-shaped structure inthe embodiment of FIG. 26 is oriented at an oblique angle relative tothe longitudinal axis of the stent with the cross-bar portion 130 of the‘H’ shaped structure extending in a circumferential direction.

In other embodiments of the invention, cross-bar portion 130 of theH-shaped member is oriented in a longitudinal direction, as shown forexample in FIG. 30, or in a circumferential direction, as shown forexample, in FIG. 31.

In the embodiment of FIG. 26, there are three overlapping regions 130between adjacent circumferential bands 104. The distal end of each cell136 is defined by two full peaks 106 and two full troughs 108 and theproximal end of each cell 136 is defined by two full peaks 106 and twofull cells 136. It is also within the scope of the invention for thereto be fewer overlapping regions 130 between adjacent circumferentialbands 104 or more overlapping regions 130 between adjacentcircumferential bands 104. In the embodiment of FIG. 27, there are fouroverlapping regions 130 between adjacent circumferential bands 104. Thedistal end of each cell 136 is defined by three full peaks 106 and threefull troughs 108 and the proximal end of each cell 136 is defined bythree full peaks 106 and three full troughs 136. The ‘H’ shapedstructures 132 extend in an oblique direction relative to thelongitudinal axis of the stent.

In the stents of FIGS. 26-37 it is also noted that the totalcircumferential length of the proximal and distal most circumferentialbands 104 a is less than the total circumferential length of the othercircumferential bands 104 b. Desirably, the difference in totalcircumferential length is on the order of 5%. In another embodiment ofthe invention, the proximal and distal most circumferential bands are ofthe same total circumferential length as the other circumferentialbands. In another embodiment of the invention, the proximal and distalmost circumferential bands are of greater total circumferential lengththan the other circumferential bands. In yet another embodiment of theinvention only of the proximal and distal most circumferential bands areof greater total circumferential length than the other circumferentialbands. In yet another embodiment of the invention only of the proximaland distal most circumferential bands are of lesser totalcircumferential length than the other circumferential bands. Finally, inyet another embodiment of the invention one of the proximal and distalmost circumferential bands is of greater total circumferential lengththan the other circumferential bands and the other of the proximal anddistal most circumferential bands is of lesser total circumferentiallength than the other circumferential bands. FIG. 26B is a schematicexample of two bands having different total circumferential lengthsbecause one circumferential band has a greater longitudinal extent thanthe other circumferential band

In the stents of FIGS. 43-45, the proximal-most and distal-mostcircumferential bands 104 a,c are of different total circumferentiallengths than the remainder of the circumferential bands 104 b. In thiscase, they are shorter than the other circumferential bands 104 b.Moreover, the proximal-most bands 104 a are of shorter total length thanthe distal-most circumferential band 104 c. In the stents of FIGS.43-45, adjacent circumferential bands 104 have regions 130 of overlap.More generally, the invention is directed to stents comprisingcircumferential bands wherein the proximal-most and distal-mostcircumferential bands are of less total circumferential length than theremainder of the circumferential bands and one of the proximal-most anddistal-most circumferential bands is shorter than the other. Thecircumferential bands may overlap one another or may be connected byconnecting which extend through gaps separating adjacent circumferentialbands.

The stents of FIGS. 43-45 is also notable in that the number ofoverlapping regions 130 alternates between 2 and 3 along the length ofthe stent. This results in alternating regions having three cells 136extending about the circumference of the stent and regions having twocells 136 extending about the circumference of the stent. Moregenerally, the invention is directed to stents having alternatingnumbers of overlapping regions or connections between adjacent bandsalong the length of the stent. Thus, the number of overlapping regionsor connections between adjacent bands will alternate between N and Mwhere N and M are different integers greater than or equal to 1. Theinvention is also directed to stents having alternating numbers of cellsin circumferential bands along the length of the stent. Thus, the numberof cells arranged about the circumference of the stent will alternatebetween N and M along the length of the stent where N and M aredifferent integers greater than or equal to 1.

The stents of FIGS. 43-45 also have more cells disposed about thecircumference at one end than at the other end.

The invention is also direct to a stent such as that shown by way ofexample in FIG. 12, comprising a plurality of circumferential bands,with adjacent circumferential bands connected one to the other via aplurality of connectors. The circumferential bands include firstcircumferential bands 104 characterized by a first number of alternatingfirst peaks 106 and first troughs 108 joined by bent struts 110 andsecond circumferential bands 12 characterized by a second number ofalternating second peaks 114 and second troughs 116 joined by bentstruts 118. The second number is different from the first number. Eachsecond circumferential band 112 is connected to one adjacent firstcircumferential band 104 via at least one connector 120 and desirably aplurality of connectors 120. The one or more connectors 120 extend frompeaks 106 on the adjacent first circumferential band 104 to peaks 114 onthe second circumferential band 112. Each second circumferential band112 is also connected to another adjacent first circumferential band 104via one or more connectors 120 extending from troughs 108 on the anotherfirst circumferential band 104 to troughs 116 on the secondcircumferential band 112.

Desirably, the connectors 120 are not straight. More desirably, as shownin FIG. 12, the connectors 120 are substantially parallel to the bentstruts 110 of the first circumferential bands 104.

In the embodiment of FIG. 12, the first and second circumferential bandsare each characterized by a longitudinal extent and the longitudinalextent of each first circumferential band 104 exceeds the longitudinalextent of each second circumferential band 112. It is also within thescope of the invention for the first and second circumferential bands tobe of the same longitudinal extent.

Also, in the embodiment of FIG. 12, the first circumferential bands 104are each characterized by a first total circumferential length and thesecond circumferential bands 112 are each characterized by a secondtotal circumferential length and the first total circumferential lengthis equal to the second total circumferential length. In otherembodiments of the invention, the first and second circumferential bandsmay be of different total circumferential lengths.

The invention is also directed to a stent, such as that shown by way ofexample in FIG. 43, comprising a plurality of serpentine circumferentialbands 104. Adjacent serpentine circumferential bands 104 are connectedone to the other. The serpentine circumferential bands 104 include afirst serpentine circumferential band 104 a having a first totalcircumferential length at a proximal end of the stent, a secondserpentine circumferential band 104 b having a second totalcircumferential length at a distal end of the stent and a thirdserpentine circumferential band 104 c having a third totalcircumferential length between the proximal and distal ends of thestent. The first and second total circumferential lengths differ fromone another. Desirably, the first, second and third totalcircumferential lengths differ from one another. More desirably, thefirst and second total circumferential lengths are less than the thirdtotal circumferential length.

As shown in FIG. 43, the serpentine circumferential bands include a band104 a of a first longitudinal extent and a band 104 b of a secondlongitudinal extent different from, and desirably, less than the firstlongitudinal extent. The first longitudinal extent is greater than thesecond longitudinal extent.

The stent may optionally have serpentine circumferential bands having afirst number of peaks and troughs and serpentine circumferential bandshaving a second number of peaks and troughs, the second number less thanthe first number, as shown for example in FIG. 12.

Desirably, as shown in FIG. 43, each serpentine circumferential band 104a-c comprises a plurality of peaks 106 and troughs 108 with bent struts110 extending between adjacent peaks 106 and troughs 108.Circumferentially adjacent bent struts 110 are nested as they are inmany other embodiments disclosed herein.

The invention is also directed to a stent such as that shown by way ofexample in FIG. 43, comprising a plurality of interconnected serpentinecircumferential bands 104 a-c, each comprising a plurality of peaks 106and troughs 108. Adjacent peaks 106 and troughs 108 are connected bybent struts 110. The bent struts 110 are arranged in a nestedrelationship. The serpentine circumferential bands 104 include a firstserpentine circumferential band 104 a having a first totalcircumferential length at a proximal end of the stent, a secondserpentine circumferential band 104 b having a second totalcircumferential length at a distal end of the stent and a thirdserpentine circumferential band 104 c having a third totalcircumferential length between the proximal and distal ends of thestent. At least one of the first and second total circumferentiallengths differs from the third total circumferential length.

Desirably, as shown in FIG. 43, both the first and second totalcircumferential lengths differ from the third total circumferentiallength. More desirably, at least one of the first and second totalcircumferential lengths is less than the third total circumferentiallength.

Adjacent serpentine circumferential bands may be connected by connectorsextending from peaks to troughs, where the connectors are shorter inlength than the bent struts. In the embodiment of FIG. 43, some of thepeaks 106 a and troughs 108 a of adjacent serpentine circumferentialbands 104 overlap one another and are joined one to the other. Theoverlapping peaks 106 a and troughs 108 a are longer than the remainingpeaks 106 and troughs 108. The regions 130 of overlap between adjacentbands extend in a direction oblique to the longitudinal axis of thestent. The region may also extend in a circumferential direction or in alongitudinal direction. Examples of overlap regions 130 extending inthese directions are shown in FIGS. 30 and 38.

The invention is also directed to a stent such as that shown in FIG. 30,comprising a plurality of serpentine circumferential bands 104. Eachserpentine circumferential band 104 comprises a plurality of peaks 106and troughs 108 which are connected by bent struts 110. Adjacentserpentine circumferential bands 104 are connected one to the other inone or more regions 130 of overlap where a peak 106 a in one serpentineband overlaps with a trough 108 a in an adjacent serpentinecircumferential band. The one or more regions 130 of overlap extendingin a longitudinal direction.

Optionally, at least one serpentine circumferential bands 104 will be ofa greater total circumferential length than other of the serpentinecircumferential bands 104. In the embodiment of FIG. 30, theproximal-most and distal-most serpentine circumferential bands 104 a areof shorter total circumferential length than the remaining serpentinecircumferential bands 104 b of the stent.

The invention is also directed to a stent, as shown by way of example inFIG. 37, comprising a plurality of serpentine circumferential bands 104where each serpentine circumferential band 104 comprises a plurality ofpeaks 106 and troughs 108. Adjacent peaks 106 and troughs 108 areconnected by nested bent struts 110. Serpentine circumferential bands104 which are adjacent one another are connected via a plurality ofconnections 130. The stent includes two serpentine circumferential bandswhich are connected via a first number of connections and two serpentinecircumferential bands which are connected via a second number ofconnections, where the second number is different from the first number.

The connections may be in the form of overlapping regions 130 of peaks106 a and troughs 108 a on adjacent serpentine circumferential bands 104or may be form of linear segments extending from one serpentinecircumferential band to another serpentine circumferential band. Anexample of the latter connectors is shown in FIG. 25.

Typically, the stent will have twice as many of the first number ofconnections as compared to the second number of connections. In theembodiment of FIG. 37, six connections are provided between theproximal-most serpentine circumferential band 104 a and the serpentinecircumferential band 104 b adjacent thereto and six connections areprovided between the distal-most serpentine circumferential band 104 cand the serpentine circumferential band 104 b adjacent thereto. Theremainder of the adjacent serpentine circumferential bands 104 b havethree connections. Other numbers of connections are also within thescope of the invention. By way of example, the proximal-most serpentinecircumferential band and the serpentine circumferential band adjacentthereto and/or the distal-most serpentine circumferential band and theserpentine circumferential band adjacent thereto may have four five, sixor more connections and the remainder of the serpentine circumferentialbands may have three connections.

The stents may optionally be constructed such that at least one of theproximal-most serpentine circumferential band and the distal-mostserpentine circumferential band is of a different total circumferentiallength than other of the serpentine circumferential bands. Typically,the proximal-most and/or distal-most serpentine circumferential bandswill be shorter in total circumferential length than the remainingbands. Moreover, the proximal-most serpentine circumferential band maybe of a different total length than the distal-most serpentinecircumferential band.

The invention is also directed to a stent such as that shown by way ofexample in FIG. 37 comprising a plurality of adjacent serpentinecircumferential bands 104 containing alternating troughs 108 and peaks106. Adjacent serpentine circumferential bands 104 have a plurality ofcells 136 therebetween. At least two adjacent serpentine circumferentialbands 104 have a plurality of first cells 136 a therebetween and aplurality of second cells 136 b therebetween. The second cells 136 b arelarger than the first cells 136 a. Desirably the first and second cells136 a,b alternate with one another about the circumference of the stent.Optionally, as shown in FIG. 37, at least two adjacent serpentinecircumferential bands 104 at the proximal end of the stent have aplurality of first cells 136 a therebetween and a plurality of secondcells 136 b therebetween, the second cells 136 b larger than the firstcells 136 a and at least two adjacent serpentine circumferential bands104 at the distal end of the stent have a plurality of first cells 136 atherebetween and a plurality of second cells 136 b therebetween, thesecond cells 136 b larger than the first cells 136 a. Desirably, thesecond cells 136 b are at least approximately twice the area of thefirst cells 136 a. In the embodiment of FIG. 37, the first cells 136 aare bounded at one end by one peak 106 and at another end by one trough108.

In some embodiments of the invention, circumferentially adjacent strutsare not parallel to one another. In the embodiments of FIGS. 40 and 43,for example, as shown in inset A, bent struts 110 comprise first region110 a and second region 110 b joined by elbow 110 c. First region 110 ais longer than second region 110 b. Each first region 110 a is at anangle α (or 180-α depending on whether first region inclines toward thedistal end of the stent or declines toward the distal end of the stent)relative to the longitudinal axis of stent and each second region 110 bis at an angle β relative to the longitudinal axis of the stent (or180-β depending on whether the second region declines toward the distalend of the stent or inclines toward the distal end of the stent). Elbow110 c subtends an angle γ given by 180-α-β. Desirably, α and β arechosen such that elbow 110 c subtends an angle γ between about 5 degreesand 90 degrees.

Each peak 104 of the stent has a first region 110 a of one bent strutand a second region 110 b of a second bent strut extending therefrom.First region 110 a and second region 110 b extending from the peak arenon-parallel to one another. Each trough 106 of the stent has a firstregion 110 a of one bent strut and a second region 110 b of a secondbent strut extending therefrom. First region 110 a and second region 110b extending from the trough are non-parallel to one another as well.

Because of the difference in length of the first and second regions andthe angles of the first and second regions, adjacent inflection points110 d of elbows 110 c on a given circumferential band are staggeredslightly in a longitudinal direction as the circumference of the stentis traversed.

These features allow for improved crimpability of the stent.

Desirably, the angle y of the elbow regions of the inventive stentsremains constant on expansion of the stent and is substantially the samein the expanded state as it is in the unexpanded state. This featurecontributes to compression resistance of the stent.

The invention is also directed to a stent comprising a plurality ofserpentine circumferential bands including a first serpentinecircumferential band comprising a plurality of peaks and troughs,adjacent peaks and troughs connected by bent struts and a secondserpentine circumferential band comprising a plurality of peaks andtroughs, adjacent peaks and troughs connected by relatively straightstruts. The first and second serpentine circumferential bands areconnected to one another. Desirably, the first and second serpentinecircumferential bands are connected one to the other via a plurality ofconnectors which optionally are straight and optionally non-parallel tothe longitudinal axis of the stent. Typically, the connectors willextend from peaks on the first serpentine circumferential bands to peakson the second serpentine circumferential band.

An example of such a stent is shown at 100 in FIG. 19. The stent of FIG.19 comprises a plurality of the first serpentine circumferential bandsand a plurality of the second serpentine circumferential bands whereserpentine circumferential bands which are adjacent one another areconnected one to the other. In the stent of FIG. 19, the first andsecond serpentine circumferential bands alternate with one another overthe length of the stent.

Any of the inventive stents disclosed above may be provided with auniform diameter or may taper in portions or along the entire length ofthe stent. Also, the width and/or thickness of the various portions ofthe inventive stents may increase or decrease along a given portion ofthe stent. For example, the width and/or thickness of thecircumferential bands and/or connectors may increase or decrease alongportions of the stent or along the entire length of the stent. Theamplitude and wavelength of several successive first circumferentialbands may remain constant while the width and/or thickness of thesuccessive first circumferential bands decrease. Similarly, theamplitude and wavelength of several successive second circumferentialbands may remain constant while the width and/or thickness of thesuccessive second circumferential bands decrease.

The inventive stents may also be provided with end effects by modifyingthe stent such that that one or both ends are more rigid or moreflexible than the remainder of the stent. Any of the inventive stentsdisclosed herein may be modified to have proximal-most and/ordistal-most circumferential bands of a greater total circumferentiallength than the remaining circumferential bands. Any of the inventivestents disclosed herein may also be modified to have proximal-mostand/or distal-most circumferential bands of a lesser totalcircumferential length than the remaining circumferential bands.Moreover, any of the inventive stents disclosed herein may also bemodified so that one of the ends has circumferential bands of a lessertotal circumferential length than the circumferential band of the otherend which in turn is longer or shorter than the total length of any ofthe remaining circumferential bands.

Also, one or both of the end circumferential bands may be modified to beof a greater longitudinal extent than the remaining circumferentialbands or to be of a lesser longitudinal extent than the remainingcircumferential bands. Each of the two end circumferential bands maydiffer in longitudinal extent with one another and with the remainingcircumferential bands.

The invention also contemplates modifying the ends of any of theinventive stents so that the two proximal-most and/or two distal-mostcircumferential bands have more connections therebetween than theremaining circumferential bands or fewer connections therebetween thanthe remaining circumferential bands.

Further, the proximal-most and/or distal-most circumferential bands maybe of a greater mass than the remaining bands or a lower mass than theremaining bands. They may be thicker than the remaining bands or thinnerthan the remaining bands.

It is understood that the above discussed modifications resulting in endeffects may be applied to multiple circumferential bands at one or bothends of the stent and are not limited to the proximal-most anddistal-most circumferential bands.

The stents disclosed herein may also be modified by employing differenttypes of connections between the circumferential bands. To that end, anyof the connectors and connector configurations disclosed herein may beused in any of the disclosed embodiments. For example, in thoseembodiments in which adjacent circumferential bands overlap, the stentmay be modified so that the adjacent circumferential bands do notoverlap and are connected by connectors extending between thecircumferential bands. Any of the connectors and connectorconfigurations may be used. Other shaped connectors may also be usedincluding those shown at 120 a-in FIG. 46. As shown in FIG. 46, theconnectors may have one or more bends therein. The connectors may extendfrom peaks to troughs, from peaks to peaks, from troughs to peaks and/orfrom troughs to troughs. The connectors may be longer than theindividual circumferential bands, which may, but need to occur withconnectors with bends therein or they may be shorter than the individualsegments.

The stents disclosed herein may also be modified by changing the numberof connections between adjacent circumferential bands. Thus, wherelarger cells are desired, fewer connections between circumferentialbands will be provided. Where smaller cells are desired, moreconnections between bands will be provided. Any of the embodiments shownmay also be modified in some portions of the stent but not others. Thus,some sections of the stent may have more connections and other sectionsmay have fewer connections. More flexibility may be achieved byproviding fewer connections between adjacent circumferential bands.

The connectors may range on width from being wider than the width of thewidest struts in the stent, to being narrower than the narrowest strutsin the stent or anywhere in between. Regions of different flexibilitymay also be achieved by using wider connection in some regions, forexample the one or both of the ends of the stent and narrower connectorsin the other regions of the stent (e.g. the middle) or vice versa

The invention also contemplates embodiments in which the spacing betweenadjacent circumferential bands varies in different portions of thestent. For example, the proximal-most circumferential band and/or thedistal-most circumferential band may be spaced further apart from thecircumferential bands adjacent thereto or may space closer thereto. Thiswould result in using longer connectors between the end bands or shorterconnectors, depending on the configuration. In one embodiment, both theproximal-most and the distal-most circumferential bands are more closelyspaced to adjacent circumferential bands than the spacing between theremaining circumferential bands and further, the spacing between theproximal-most circumferential band and the circumferential band adjacentthereto differs from the spacing between the distal-most circumferentialband and the circumferential band adjacent thereto.

It is also within the scope of the invention for any of the stentdisclosed herein to have connectors extending from regions other thanpeaks and trough or corners of peaks and troughs. For example, theconnectors may extend from positions midway between adjacent peaks andtroughs, from position one quarter of the way between peaks and troughs,from positions three quarters of the way between peaks and troughs oranywhere else between peaks and troughs.

As shown in the various embodiments, the connections betweencircumferential bands may extend in a longitudinal direction or may havefirst and second ends which are circumferentially and longitudinallyoffset from one another, as in the case of connections extending at anoblique angle. The connections may also include portions which arenon-parallel to the longitudinal axis of the stent.

The ‘phase relationship’ between adjacent circumferential bands may alsobe modified in any of the embodiments. For example, in embodiments ofthe invention such as that of FIG. 24, peaks of adjacent cylindricalbands may be in longitudinal alignment with one another or may beunaligned with one another in the longitudinal direction. Similarly,peaks on one band may be longitudinally aligned with troughs on anadjacent circumferential band or may be unaligned with troughs on anadjacent circumferential band. Some of the adjacent circumferentialbands may be aligned while other adjacent bands may not be aligned.

Bent struts as referred to herein typically have two segments joined bya bent portion. The segments are straight as shown in the figures butmay also be curved. The bent struts may be modified to have more thanone bend. For example, a strut having three or more segments and two ormore bends may also be used. More generally, substantially bow shapedstruts may be used.

The stent patterns disclosed herein may also be used for bifurcatedstents. One or more legs and/or the trunk of a bifurcated stent may beprovided with any of the stent designs disclosed herein.

The inventive stents may be manufactured using known stent manufacturingtechniques. Suitable methods for manufacturing the inventive stentsinclude laser cutting, chemical etching or stamping of a tube. Theinventive stents may also be manufactured by laser cutting, chemicallyetching, stamping a flat sheet, rolling the sheet and, optionally,welding the sheet. Other suitable manufacturing techniques includeelectrode discharge machining or molding the stent with the desireddesign.

The stent may also be manufactured by welding individual sections, forexample, circumferential bands, together. Any other suitable stentmanufacturing process may also be used.

Any suitable stent material may be used in the manufacture of theinventive stents. Examples of such materials include polymericmaterials, metals, ceramics and composites. Suitable polymeric materialsinclude thermotropic liquid crystal polymers (LCP's). Where the stent ismade of metal, the metal may be stainless steel, cobalt chrome alloyssuch as elgiloy, tantalum or other plastically deformable metals. Othersuitable metals include shape-memory metals such as nickel-titaniumalloys generically known as “nitinol”, platinum/tungsten alloys andtitanium alloys.

The invention also contemplates the use of more than one material in theinventive stents. For example, the first undulating bands and the secondundulating bands may be made of different materials. Optionally, theconnectors may be made of a different material than the first and/orsecond undulating bands.

The inventive stents may be provided in mechanically expandable form, inself-expanding form or as a hybrid of the two. Mechanically expandablestents, in accordance with the invention, may be expanded using anysuitable mechanical device including a balloon.

The inventive stents may include suitable radiopaque coatings. Forexample, the stents may be coated with gold or other noble metals orsputtered with tantalum or other metals. The stents may also be madedirectly from a radiopaque material to obviate the need for a radiopaquecoating or may be made of a material having a radiopaque inner core.Other radiopaque metals which may be used include platinum,platinum-tungsten, palladium, platinum-iridium, rhodium, tantalum, oralloys or composites of these metals.

The inventive stents may also be provided with various bio-compatiblecoatings to enhance various properties of the stent. For example, theinventive stents may be provided with lubricious coatings. The inventivestents may also be provided with drug-containing coatings which releasedrugs over time. The increased surface area of a stent having bentstruts provides for increased drug coatability. The bent struts alsoprovide for point contact with a crimper versus strut/strut contact.Less contact with the crimper results in less disruption of the drugcoating.

The inventive stents may also be provided with a sugar or more generallya carbohydrate and/or a gelatin to maintain the stent on a balloonduring delivery of the stent to a desired bodily location. Othersuitable compounds for treating the stent include biodegradable polymersand polymers which are dissolvable in bodily fluids. Portions of theinterior and/or exterior of the stent may be coated or impregnated withthe compound. Mechanical retention devices may also be used to maintainthe stent on the balloon during delivery. To that end, the use of othercoatings on the inventive stents is also within the scope of theinvention.

The coating may comprise one or more non-genetic therapeutic agents,genetic materials and cells and combinations thereof as well as otherpolymeric coatings.

Non-genetic therapeutic agents include anti-thrombogenic agents such asheparin, heparin derivatives, urokinase, and PPack (dextrophenylalanineproline arginine chloromethylketone); anti-proliferative agents such asenoxaprin, angiopeptin, or monoclonal antibodies capable of blockingsmooth muscle cell proliferation, hirudin, and acetylsalicylic acid;anti-inflammatory agents such as dexamethasone, prednisolone,corticosterone, budesonide, estrogen, sulfasalazine, and mesalamine;antineoplastic/antiproliferative/anti-miotic agents such as paclitaxel,5-fluorouracil, cisplatin, vinblastine, vincristine, epothilones,endostatin, angiostatin and thymidine kinase inhibitors; anestheticagents such as lidocaine, bupivacaine, and ropivacaine; anti-coagulantssuch as D-Phe-Pro-Arg chloromethyl keton, an RGD peptide-containingcompound, heparin, antithrombin compounds, platelet receptorantagonists, anti-thrombin anticodies, anti-platelet receptorantibodies, aspirin, prostaglandin inhibitors, platelet inhibitors andtick antiplatelet peptides; vascular cell growth promotors such asgrowth factor inhibitors, growth factor receptor antagonists,transcriptional activators, and translational promotors;

Vascular cell growth inhibitors such as growth factor inhibitors, growthfactor receptor antagonists, transcriptional repressors, translationalrepressors, replication inhibitors, inhibitory antibodies, antibodiesdirected against growth factors, bifunctional molecules consisting of agrowth factor and a cytotoxin, bifunctional molecules consisting of anantibody and a cytotoxin; cholesterol-lowering agents; vasodilatingagents; and agents which interfere with endogenous vascoactivemechanisms.

Genetic materials include anti-sense DNA and RNA, DNA coding for,anti-sense RNA, tRNA or rRNA to replace defective or deficientendogenous molecules, angiogenic factors including growth factors suchas acidic and basic fibroblast growth factors, vascular endothelialgrowth factor, epidermal growth factor, transforming growth factor.alpha. and .beta., platelet-derived endothelial growth factor,platelet-derived growth factor, tumor necrosis factor .alpha.,hepatocyte growth factor and insulin like growth factor, cell cycleinhibitors including CD inhibitors, thymidine kinase (“TK”) and otheragents useful for interfering with cell proliferation the family of bonemorphogenic proteins (“BMP's”), BMP-2, BMP-3, BMP-4, BMP-5, BMP-6(Vgr-1), BMP-7 (OP-1), BMP-8, BMP-9, BMP-10, BMP-11, BMP-12, BMP-13,BMP-14, BMP-15, and BMP-16. Desirable BMP's are any of BMP-2, BMP-3,BMP-4, BMP-5, BMP-6 and BMP-7. These dimeric proteins can be provided ashomodimers, heterodimers, or combinations thereof, alone or togetherwith other molecules. Alternatively or, in addition, molecules capableof inducing an upstream or downstream effect of a BMP can be provided.Such molecules include any of the “hedgehog” proteins, or the DNA'sencoding them.

Cells can be of human origin (autologous or allogeneic) or from ananimal source (xenogeneic), genetically engineered if desired to deliverproteins of interest at the transplant site. The cells may be providedin a delivery media. The delivery media may be formulated as needed tomaintain cell function and viability.

Suitable polymer coating materials include polycarboxylic acids,cellulosic polymers, including cellulose acetate and cellulose nitrate,gelatin, polyvinylpyrrolidone, cross-linked polyvinylpyrrolidone,polyanhydrides including maleic anhydride polymers, polyamides,polyvinyl alcohols, copolymers of vinyl monomers such as EVA, polyvinylethers, polyvinyl aromatics, polyethylene oxides, glycosaminoglycans,polysaccharides, polyesters including polyethylene terephthalate,polyacrylamides, polyethers, polyether sulfone, polycarbonate,polyalkylenes including polypropylene, polyethylene and high molecularweight polyethylene, halogenated polyalkylenes includingpolytetrafluoroethylene, polyurethanes, polyorthoesters, proteins,polypeptides, silicones, siloxane polymers, polylactic acid,polyglycolic acid, polycaprolactone, polyhydroxybutyrate valerate andblends and copolymers thereof, coatings from polymer dispersions such aspolyurethane dispersions (for example, BAYHDROL®), fibrin, collagen andderivatives thereof, polysaccharides such as celluloses, starches,dextrans, alginates and derivatives, hyaluronic acid, squaleneemulsions. Polyacrylic acid, available as HYDROPLUS® (Boston ScientificCorporation, Natick, Mass.), and described in U.S. Pat. No. 5,091,205,the disclosure of which is hereby incorporated herein by reference, isparticularly desirable. Even more desirable is a copolymer of polylacticacid and polycaprolactone.

The inventive stents may also be used as the framework for a graft.Suitable coverings include nylon, collagen, PTFE and expanded PTFE,polyethylene terephthalate and KEVLAR, or any of the materials disclosedin U.S. Pat. Nos. 5,824,046 and 5,755,770. More generally, any knowngraft material may be used including synthetic polymers such aspolyethylene, polypropylene, polyurethane, polyglycolic acid,polyesters, polyamides, their mixtures, blends and copolymers.

The inventive stents may find use in coronary arteries, renal arteries,peripheral arteries including iliac arteries, arteries of the neck andcerebral arteries. The stents of the present invention, however, are notlimited to use in the vascular system and may also be advantageouslyemployed in other body structures, including but not limited toarteries, veins, biliary ducts, urethras, fallopian tubes, bronchialtubes, the trachea, the esophagus, the prostate and the bowels.

Suitable stent delivery devices such as those disclosed in U.S. Pat.Nos. 6,123,712, 6,120,522 and 5,957,930 may be used to deliver theinventive stents to the desired bodily location. The choice of deliverydevice will depend on whether a self-expanding or balloon expandablestent is used. The inventive stents may be delivered in conjunction withone or more stent retaining sleeves. An example of stent retainingsleeves is disclosed in U.S. provisional application No. 60/238,178.

The above disclosure is intended to be illustrative and not exhaustive.This description will suggest many variations and alternatives to one ofordinary skill in this art. All these alternatives and variations areintended to be included within the scope of the claims where the term“comprising” means “including, but not limited to”.

Those familiar with the art may recognize other equivalents to thespecific embodiments described herein which equivalents are alsointended to be encompassed by the claims.

Further, the particular features presented in the dependent claims canbe combined with each other in other manners within the scope of theinvention such that the invention should be recognized as alsospecifically directed to other embodiments having any other possiblecombination of the features of the dependent claims. For instance, forpurposes of claim publication, any dependent claim which follows shouldbe taken as alternatively written in a multiple dependent form from allprior claims which possess all antecedents referenced in such dependentclaim if such multiple dependent format is an accepted format within thejurisdiction (e.g. each claim depending directly from claim 1 should bealternatively taken as depending from all previous claims). Injurisdictions where multiple dependent claim formats are restricted, thefollowing dependent claims should each be also taken as alternativelywritten in each singly dependent claim format which creates a dependencyfrom a prior antecedent-possessing claim other than the specific claimlisted in such dependent claim below (e.g. claim 3 may be taken asalternatively dependent from claim 1; claim 4 may be taken asalternatively dependent on claim 3, or on claim 1, claim 5 may be takenas alternatively dependent on claim 4, claim 3, or on claim 1; etc.).

The disclosure is intended to be illustrative and not exhaustive. Thisdescription will suggest many variations and alternatives to one ofordinary skill in this art. All these alternatives and variations areintended to be included within the scope of the attached claims. Thosefamiliar with the art may recognize other equivalents to the specificembodiments described herein which equivalents are also intended to beencompassed by the claims attached hereto.

The invention claimed is:
 1. A stent having a uniform diameter andcomprising a plurality of serpentine circumferential bands, eachserpentine circumferential band comprising a plurality of peaks andtroughs and forming a closed path about a longitudinal axis of thestent, adjacent peaks and troughs connected by bent struts, adjacentserpentine circumferential bands connected one to the other, theserpentine circumferential bands including a first serpentinecircumferential band having a first total circumferential length at aproximal end of the stent, a second serpentine circumferential bandhaving a second total circumferential length at a distal end of thestent and a third serpentine circumferential band having a third totalcircumferential length between the proximal and distal ends of thestent, a total circumferential length being the length of the closedpath, wherein at least one of the first and second total circumferentiallengths differ from the third total circumferential length; wherein someof the peaks and troughs of adjacent serpentine circumferential bandsoverlap one another and are joined one to the other; and wherein theoverlapping peaks and troughs are longer than the remaining peaks andtroughs.
 2. A stent having a uniform diameter and comprising a pluralityof serpentine circumferential bands, each serpentine circumferentialband comprising a plurality of peaks and troughs and forming a closedpath about a longitudinal axis of the stent, adjacent peaks and troughsconnected by bent struts, adjacent serpentine circumferential bandsconnected one to the other, the serpentine circumferential bandsincluding a first serpentine circumferential band having a first totalcircumferential length at a proximal end of the stent, a secondserpentine circumferential band having a second total circumferentiallength at a distal end of the stent and a third serpentinecircumferential band having a third total circumferential length betweenthe proximal and distal ends of the stent, a total circumferentiallength being the length of the closed path, wherein at least one of thefirst and second total circumferential lengths differ from the thirdtotal circumferential length; wherein some of the peaks and troughs ofadjacent serpentine circumferential bands overlap one another forming aregion of overlap, the region of overlap extending in a longitudinaldirection.
 3. A stent having a uniform diameter and comprising aplurality of serpentine circumferential bands, each serpentinecircumferential band comprising a plurality of peaks and troughs andforming a closed path about a longitudinal axis of the stent, adjacentpeaks and troughs connected by bent struts, adjacent serpentinecircumferential bands connected one to the other, the serpentinecircumferential bands including a first serpentine circumferential bandhaving a first total circumferential length at a proximal end of thestent, a second serpentine circumferential band having a second totalcircumferential length at a distal end of the stent and a thirdserpentine circumferential band having a third total circumferentiallength between the proximal and distal ends of the stent, a totalcircumferential length being the length of the closed path, wherein atleast one of the first and second total circumferential lengths differfrom the third total circumferential length; wherein some of the peaksand troughs of adjacent serpentine circumferential bands overlap oneanother forming a region of overlap, the region of overlap extending inan oblique direction relative to the longitudinal axis of the stent. 4.A stent comprising a plurality of serpentine circumferential bandsforming a closed path about a longitudinal axis of the stent, eachserpentine circumferential band comprising a plurality of peaks andtroughs, adjacent peaks and troughs connected by bent struts, each bentstrut having a single bend, adjacent serpentine circumferential bandsconnected one to the other in one or more regions of overlap where apeak in one serpentine band overlaps with a trough in an adjacentserpentine circumferential band, the one or more regions of overlapextending in a longitudinal direction.
 5. The stent of claim 4 whereinat least one serpentine circumferential band is of a greater totalcircumferential length than other of the serpentine circumferentialbands, a total circumferential length being the length of the closedpath.
 6. The stent of claim 4, wherein bent struts which arecircumferentially adjacent one another in a circumferential band areparallel to one another.
 7. The stent of claim 4, wherein some of thepeaks and troughs of adjacent serpentine circumferential bands do notoverlap one another and are aligned.
 8. A stent having a uniformdiameter and comprising a plurality of serpentine circumferential bands,each serpentine circumferential band comprising a plurality of peaks andtroughs and forming a closed path about a longitudinal axis of thestent, adjacent peaks and troughs connected by bent struts, adjacentserpentine circumferential bands connected one to the other, theserpentine circumferential bands including a first serpentinecircumferential band having a first total circumferential length at aproximal end of the stent, a second serpentine circumferential bandhaving a second total circumferential length at a distal end of thestent and a third serpentine circumferential band having a third totalcircumferential length between the proximal and distal ends of thestent, a total circumferential length being the length of the closedpath, wherein at least one of the first and second total circumferentiallengths differ from the third total circumferential length; wherein someof the peaks and troughs of adjacent serpentine circumferential bandsoverlap one another and are joined one to the other; and wherein some ofthe peaks and troughs of adjacent serpentine circumferential bands donot overlap one another and are aligned.